1. Field of the Invention
The present invention relates generally to disk array technology, and more particularly, to a storage control device, a storage system, and a method of controlling the same that can be applied to different storage management procedures.
2. Description of the Related Art
Recently, Storage Area Network (hereafter, abbreviated as SAN) environments are becoming well developed. In a SAN environment, storages with increased capacity and performance are constructed on networks. Also, as various host computers are connected, means for interoperable data interchanging becomes necessary, and the need is increasing for Network Attached Storage (hereafter, abbreviated as NAS) in SAN environments. As a result, a manager which manages and controls a storage in a SAN environment becomes essential.
Connection between a storage and a host computer in a current SAN environment is carried out through Block Storage access of SCSI (Small Computer System Interface) according to Fibre Channel. On the other hand, in a NAS environment, connection is realized through network protocols such as Network File System (hereafter, abbreviated as NFS) over Ethernet. These connections are respectively structured by dedicated networks for connection.
References where such storage management technology is disclosed are found in these documents: Japanese Patent Application Laid-open Publication Nos. 9-265355, 9-152944, 10-199136, and 2000-348005.
Further, among present storage management procedures, there are known the in-band mode and the out-of-band mode. The in-band mode uses a storage interface for connecting with a host computer. The out-of-band mode uses an interface physically and logically different from an interface for acquiring storage data from a host computer.
The mode to be used is determined in order to conform to different purposes and in accordance with the arrangement of host applications and installed interfaces.
Where a storage and a host computer (external device) are connected by Fibre Channel, systems using optical fiber as a medium are largely used. Even with a NAS, connection with optical fiber as a medium is employed for backbone components of an Ethernet.
However, even if the optical fibers are physically the same medium, each is connected with a different purpose. Therefore, since the features, including switches and/or hubs involved, differ, identical media cannot be used.
As regards storage management interface, in the instance of the in-band mode using a host-computer connection interface, there are advantages such as fast acquisition of information via a data transfer interface from a host computer and capability to easily cooperate with an application. However, unless the host computer is in operation, storage management cannot be carried out. In the instance of the out-of-band mode using, for example, a network interface separately from a host-computer connection interface, management can be carried out independently of the host computer, so maintenance can be carried out easily. However, it is necessary to provide a dedicated line separate from the host-computer connection interface. Further, as the acquirable information differs among each of the modes, the manageable information with a cooperating application is limited.